These secessionists have an advantage over those seeking outright
separation from the Union – and a big disadvantage. On one hand, they
don’t have to deal with the Confederacy/slavery baggage that tends to confound discussions of secession in the U.S. On the other hand, the Constitution, Art. IV, sec. 3 clearly forbids the
creating a new state in the territory of an existing one without the
latter’s consent, and the consent of Congress. That is a high bar,
practically insurmountable.

But there may be an easier way for those who seek to secede from
their state – instead of creating a new “51st” state, secede to join an
existing state. The Constitution’s requirement of home-state and
congressional consent only clearly applies to the creation of a “new
state."